linux/net/batman-adv/send.c
Sven Eckelmann 76543d14ae batman-adv: Explicitly mark the common header structure
All batman-adv packets have a common 3 byte header. It can be used to share
some code between different code paths, but it was never explicit stated that
this header has to be always the same for all packets. Therefore, new code
changes always have the problem that they may accidently introduce regressions
by moving some elements around.

A new structure is introduced that contains the common header and makes it
easier visible that these 3 bytes have to be the same for all on-wire packets.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
2012-02-17 02:50:19 +08:00

412 lines
11 KiB
C

/*
* Copyright (C) 2007-2011 B.A.T.M.A.N. contributors:
*
* Marek Lindner, Simon Wunderlich
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of version 2 of the GNU General Public
* License as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA
*
*/
#include "main.h"
#include "send.h"
#include "routing.h"
#include "translation-table.h"
#include "soft-interface.h"
#include "hard-interface.h"
#include "vis.h"
#include "gateway_common.h"
#include "originator.h"
#include "bat_ogm.h"
static void send_outstanding_bcast_packet(struct work_struct *work);
/* send out an already prepared packet to the given address via the
* specified batman interface */
int send_skb_packet(struct sk_buff *skb, struct hard_iface *hard_iface,
const uint8_t *dst_addr)
{
struct ethhdr *ethhdr;
if (hard_iface->if_status != IF_ACTIVE)
goto send_skb_err;
if (unlikely(!hard_iface->net_dev))
goto send_skb_err;
if (!(hard_iface->net_dev->flags & IFF_UP)) {
pr_warning("Interface %s is not up - can't send packet via "
"that interface!\n", hard_iface->net_dev->name);
goto send_skb_err;
}
/* push to the ethernet header. */
if (my_skb_head_push(skb, sizeof(*ethhdr)) < 0)
goto send_skb_err;
skb_reset_mac_header(skb);
ethhdr = (struct ethhdr *) skb_mac_header(skb);
memcpy(ethhdr->h_source, hard_iface->net_dev->dev_addr, ETH_ALEN);
memcpy(ethhdr->h_dest, dst_addr, ETH_ALEN);
ethhdr->h_proto = __constant_htons(ETH_P_BATMAN);
skb_set_network_header(skb, ETH_HLEN);
skb->priority = TC_PRIO_CONTROL;
skb->protocol = __constant_htons(ETH_P_BATMAN);
skb->dev = hard_iface->net_dev;
/* dev_queue_xmit() returns a negative result on error. However on
* congestion and traffic shaping, it drops and returns NET_XMIT_DROP
* (which is > 0). This will not be treated as an error. */
return dev_queue_xmit(skb);
send_skb_err:
kfree_skb(skb);
return NET_XMIT_DROP;
}
static void realloc_packet_buffer(struct hard_iface *hard_iface,
int new_len)
{
unsigned char *new_buff;
new_buff = kmalloc(new_len, GFP_ATOMIC);
/* keep old buffer if kmalloc should fail */
if (new_buff) {
memcpy(new_buff, hard_iface->packet_buff,
BATMAN_OGM_LEN);
kfree(hard_iface->packet_buff);
hard_iface->packet_buff = new_buff;
hard_iface->packet_len = new_len;
}
}
/* when calling this function (hard_iface == primary_if) has to be true */
static int prepare_packet_buffer(struct bat_priv *bat_priv,
struct hard_iface *hard_iface)
{
int new_len;
new_len = BATMAN_OGM_LEN +
tt_len((uint8_t)atomic_read(&bat_priv->tt_local_changes));
/* if we have too many changes for one packet don't send any
* and wait for the tt table request which will be fragmented */
if (new_len > hard_iface->soft_iface->mtu)
new_len = BATMAN_OGM_LEN;
realloc_packet_buffer(hard_iface, new_len);
atomic_set(&bat_priv->tt_crc, tt_local_crc(bat_priv));
/* reset the sending counter */
atomic_set(&bat_priv->tt_ogm_append_cnt, TT_OGM_APPEND_MAX);
return tt_changes_fill_buffer(bat_priv,
hard_iface->packet_buff + BATMAN_OGM_LEN,
hard_iface->packet_len - BATMAN_OGM_LEN);
}
static int reset_packet_buffer(struct bat_priv *bat_priv,
struct hard_iface *hard_iface)
{
realloc_packet_buffer(hard_iface, BATMAN_OGM_LEN);
return 0;
}
void schedule_bat_ogm(struct hard_iface *hard_iface)
{
struct bat_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
struct hard_iface *primary_if;
int tt_num_changes = -1;
if ((hard_iface->if_status == IF_NOT_IN_USE) ||
(hard_iface->if_status == IF_TO_BE_REMOVED))
return;
/**
* the interface gets activated here to avoid race conditions between
* the moment of activating the interface in
* hardif_activate_interface() where the originator mac is set and
* outdated packets (especially uninitialized mac addresses) in the
* packet queue
*/
if (hard_iface->if_status == IF_TO_BE_ACTIVATED)
hard_iface->if_status = IF_ACTIVE;
primary_if = primary_if_get_selected(bat_priv);
if (hard_iface == primary_if) {
/* if at least one change happened */
if (atomic_read(&bat_priv->tt_local_changes) > 0) {
tt_commit_changes(bat_priv);
tt_num_changes = prepare_packet_buffer(bat_priv,
hard_iface);
}
/* if the changes have been sent often enough */
if (!atomic_dec_not_zero(&bat_priv->tt_ogm_append_cnt))
tt_num_changes = reset_packet_buffer(bat_priv,
hard_iface);
}
if (primary_if)
hardif_free_ref(primary_if);
bat_ogm_schedule(hard_iface, tt_num_changes);
}
static void forw_packet_free(struct forw_packet *forw_packet)
{
if (forw_packet->skb)
kfree_skb(forw_packet->skb);
if (forw_packet->if_incoming)
hardif_free_ref(forw_packet->if_incoming);
kfree(forw_packet);
}
static void _add_bcast_packet_to_list(struct bat_priv *bat_priv,
struct forw_packet *forw_packet,
unsigned long send_time)
{
INIT_HLIST_NODE(&forw_packet->list);
/* add new packet to packet list */
spin_lock_bh(&bat_priv->forw_bcast_list_lock);
hlist_add_head(&forw_packet->list, &bat_priv->forw_bcast_list);
spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
/* start timer for this packet */
INIT_DELAYED_WORK(&forw_packet->delayed_work,
send_outstanding_bcast_packet);
queue_delayed_work(bat_event_workqueue, &forw_packet->delayed_work,
send_time);
}
/* add a broadcast packet to the queue and setup timers. broadcast packets
* are sent multiple times to increase probability for being received.
*
* This function returns NETDEV_TX_OK on success and NETDEV_TX_BUSY on
* errors.
*
* The skb is not consumed, so the caller should make sure that the
* skb is freed. */
int add_bcast_packet_to_list(struct bat_priv *bat_priv,
const struct sk_buff *skb, unsigned long delay)
{
struct hard_iface *primary_if = NULL;
struct forw_packet *forw_packet;
struct bcast_packet *bcast_packet;
struct sk_buff *newskb;
if (!atomic_dec_not_zero(&bat_priv->bcast_queue_left)) {
bat_dbg(DBG_BATMAN, bat_priv, "bcast packet queue full\n");
goto out;
}
primary_if = primary_if_get_selected(bat_priv);
if (!primary_if)
goto out_and_inc;
forw_packet = kmalloc(sizeof(*forw_packet), GFP_ATOMIC);
if (!forw_packet)
goto out_and_inc;
newskb = skb_copy(skb, GFP_ATOMIC);
if (!newskb)
goto packet_free;
/* as we have a copy now, it is safe to decrease the TTL */
bcast_packet = (struct bcast_packet *)newskb->data;
bcast_packet->header.ttl--;
skb_reset_mac_header(newskb);
forw_packet->skb = newskb;
forw_packet->if_incoming = primary_if;
/* how often did we send the bcast packet ? */
forw_packet->num_packets = 0;
_add_bcast_packet_to_list(bat_priv, forw_packet, delay);
return NETDEV_TX_OK;
packet_free:
kfree(forw_packet);
out_and_inc:
atomic_inc(&bat_priv->bcast_queue_left);
out:
if (primary_if)
hardif_free_ref(primary_if);
return NETDEV_TX_BUSY;
}
static void send_outstanding_bcast_packet(struct work_struct *work)
{
struct hard_iface *hard_iface;
struct delayed_work *delayed_work =
container_of(work, struct delayed_work, work);
struct forw_packet *forw_packet =
container_of(delayed_work, struct forw_packet, delayed_work);
struct sk_buff *skb1;
struct net_device *soft_iface = forw_packet->if_incoming->soft_iface;
struct bat_priv *bat_priv = netdev_priv(soft_iface);
spin_lock_bh(&bat_priv->forw_bcast_list_lock);
hlist_del(&forw_packet->list);
spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
if (atomic_read(&bat_priv->mesh_state) == MESH_DEACTIVATING)
goto out;
/* rebroadcast packet */
rcu_read_lock();
list_for_each_entry_rcu(hard_iface, &hardif_list, list) {
if (hard_iface->soft_iface != soft_iface)
continue;
/* send a copy of the saved skb */
skb1 = skb_clone(forw_packet->skb, GFP_ATOMIC);
if (skb1)
send_skb_packet(skb1, hard_iface, broadcast_addr);
}
rcu_read_unlock();
forw_packet->num_packets++;
/* if we still have some more bcasts to send */
if (forw_packet->num_packets < 3) {
_add_bcast_packet_to_list(bat_priv, forw_packet,
((5 * HZ) / 1000));
return;
}
out:
forw_packet_free(forw_packet);
atomic_inc(&bat_priv->bcast_queue_left);
}
void send_outstanding_bat_ogm_packet(struct work_struct *work)
{
struct delayed_work *delayed_work =
container_of(work, struct delayed_work, work);
struct forw_packet *forw_packet =
container_of(delayed_work, struct forw_packet, delayed_work);
struct bat_priv *bat_priv;
bat_priv = netdev_priv(forw_packet->if_incoming->soft_iface);
spin_lock_bh(&bat_priv->forw_bat_list_lock);
hlist_del(&forw_packet->list);
spin_unlock_bh(&bat_priv->forw_bat_list_lock);
if (atomic_read(&bat_priv->mesh_state) == MESH_DEACTIVATING)
goto out;
bat_ogm_emit(forw_packet);
/**
* we have to have at least one packet in the queue
* to determine the queues wake up time unless we are
* shutting down
*/
if (forw_packet->own)
schedule_bat_ogm(forw_packet->if_incoming);
out:
/* don't count own packet */
if (!forw_packet->own)
atomic_inc(&bat_priv->batman_queue_left);
forw_packet_free(forw_packet);
}
void purge_outstanding_packets(struct bat_priv *bat_priv,
const struct hard_iface *hard_iface)
{
struct forw_packet *forw_packet;
struct hlist_node *tmp_node, *safe_tmp_node;
bool pending;
if (hard_iface)
bat_dbg(DBG_BATMAN, bat_priv,
"purge_outstanding_packets(): %s\n",
hard_iface->net_dev->name);
else
bat_dbg(DBG_BATMAN, bat_priv,
"purge_outstanding_packets()\n");
/* free bcast list */
spin_lock_bh(&bat_priv->forw_bcast_list_lock);
hlist_for_each_entry_safe(forw_packet, tmp_node, safe_tmp_node,
&bat_priv->forw_bcast_list, list) {
/**
* if purge_outstanding_packets() was called with an argument
* we delete only packets belonging to the given interface
*/
if ((hard_iface) &&
(forw_packet->if_incoming != hard_iface))
continue;
spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
/**
* send_outstanding_bcast_packet() will lock the list to
* delete the item from the list
*/
pending = cancel_delayed_work_sync(&forw_packet->delayed_work);
spin_lock_bh(&bat_priv->forw_bcast_list_lock);
if (pending) {
hlist_del(&forw_packet->list);
forw_packet_free(forw_packet);
}
}
spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
/* free batman packet list */
spin_lock_bh(&bat_priv->forw_bat_list_lock);
hlist_for_each_entry_safe(forw_packet, tmp_node, safe_tmp_node,
&bat_priv->forw_bat_list, list) {
/**
* if purge_outstanding_packets() was called with an argument
* we delete only packets belonging to the given interface
*/
if ((hard_iface) &&
(forw_packet->if_incoming != hard_iface))
continue;
spin_unlock_bh(&bat_priv->forw_bat_list_lock);
/**
* send_outstanding_bat_packet() will lock the list to
* delete the item from the list
*/
pending = cancel_delayed_work_sync(&forw_packet->delayed_work);
spin_lock_bh(&bat_priv->forw_bat_list_lock);
if (pending) {
hlist_del(&forw_packet->list);
forw_packet_free(forw_packet);
}
}
spin_unlock_bh(&bat_priv->forw_bat_list_lock);
}